Does The Live Nasal Flu Vaccine Work? The CDC Doesn't Seem To Think So

Now that summer's winding down, flu season is coming up, and it's time to prepare your children (and yourself) with some sort of vaccine. For those who hate the thought of needles, the advent of the nasal flu vaccine seemed like a godsend. But the preventative measure has been facing some controversy lately, with differing reports on whether the live nasal flu vaccine works as well as it's supposed to. In a move that surprised everyone, the CDC recently recommended against the vaccine, and now some researchers are fighting back.

In a media statement on June 22, the Centers for Disease Control and Prevention, which recommends annual flu vaccination for everyone over 6 months of age, revealed that its advisory committee voted against the nasal spray being used to vaccinate for the upcoming year. According to the data the committee collected, the nasal spray showed almost no measurable protective benefit, while the inactivated flu shot showed much stronger protection. The CDC had previously recommended the nasal spray, so the reversal shocked a lot of people.

And one Canadian study published on Monday showed some strong evidence that the live nasal flu vaccine does work almost as well as the shot (citing a 5.3 percent infection rate for nasal compared to a 5.2 percent rate for the shot in the rural Canadian populations studied), adding to the confusion.

The vaccine has changed over the last few years in the United States, from a trivalent one that included three strains of flu to a quadrivalent one that included four. As NPR's Tara Haelle points out, some of the contradictory evidence may spring from the fact that researchers in the Canadian study used the trivalent form of the spray while the CDC researched the newer quadrivalent one. (The trivalent form had always done very well in CDC testing.) It seems that, in striving to be more effective, the nasal spray flu vaccine actually got worse.

Other possible reasons for the differences in the study results include the populations studied (rural Canadians versus Americans) and the study methods (survey versus observation).

So what should you do if you had your heart set on getting some mist shot up your nose? It's probably better to be safe than sorry — get yourself a regular flu shot this year if you want to be really safe. Perhaps by next year, the United States will have returned to the previous, more effective version of the spray, and you'll never have to deal with a needle again.